Platen lock



H. F. E. BAESELER.

PLATEN' LOCK.

APPLICATlON FILED OCT. 12, 1920.

n. Q IE 1 .26 6 MW 3 fis 1h 4 w r wi a d v m A r m m H. F. E. BAESELER.

PLATEN LOCK.

APPLICATION FILED OCT-12, 1920- 1326,24, PatentedAug.15, 1922.

2 SHEETS-SHEET 2.

java]? for @ZZTZZ'JQ 21:22: Baese Zer HEINRICH FRANZ EDMUND BAESELER, OF DRESDEN, GERMANY, ASSIGNOR TO AKT. v GES. "VOBM SEIDEL & NAUMANN, OF DRESDEN, GERMANY, A CORPORATION OF GERMANY.

PLATEN LOCK.

Specification of Letters Patent. Patented A 15 1922 Application filed October 12, 1920. Serial No. 416,575.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. I, 1313.)

T 0 all whom it may concern:

Be'it known that I, Hninrlori FRANZ E1 MUND BAESELER, a citizen of the German Republic, and resident of Dresden, Germany, have invented certain new and useful Improvements in Platen Looks (for which I have filed application in Germany, Apr. 28, 1919; in Austria, June 10, 1918; in Sweden, June 17, 1918; in Hungary, June 18, 1918; in Switzerland, June 30, 1918; in Italy, July 15, 1918; in France, July 31, 1918, Patent No. 511,688; in England, Aug. 27, 1919), of which the following is a specification.

The invention relates to type writing machines with shift-ably arranged platen and the purpose of the invention is to prevent the rebounding and repeated upward movement of the platen at the return from the shifting position into the position of rest or normal position, and thereby to insure a uniform and exact impression of the type, and to prevent furthermore the objectionable shaking of the platen frame at the inserting 'or extracting of the paper sheet.

For obviating this disadvantage it has been already proposed to provide locking members on the carriage frame for the purposeof locking the platen frame thereto. The desired purpose,'however, has not been attained by this arrangement as the turnlng point of said lockin members does not participate in the shi 'ting movement of the platen frame and accordingly the turning movement of the locking members either continued during the whole shifting operat on or special means were required for hunting the turning movement of the loclnng members. Furthermore in the known arrangement at the return movement of the locking members a considerable friction is produced in consequence of which the complete falling back of the platen is impeded.

According to the present invention and for obviating this defect the locking members are arranged on the platen frame in such a manner that each of them in the position of rest of the carriage engages under a pin or the like provided on said carriage. Hereby not only an oscillating movement of the locking members, which is asshght as possible is obtained, but also special means for limiting said oscillating movement are rendered unnecessary. The arrangement itself is very simple and insures a frictionless return of the carriage.

Thelocking members can carry the guiding rall of the carriage frame and are alone operated by the latter by means of the shifting roll during the first 'part only of the movement of the latter to release the platen frame from thelcarriage.

The locking members may also be connected to a special rail parallel to the guiding rail proper of the platen frame by means of which special rail the locking members can be oscillated out of the locking position before the adjustment or shifting of the guiding rail.

In the accompanying drawings, illustrating two forms of execution of the subject matter of this'invention, only those parts of a type writing machine are shown, which are necessary for comprehending the invenof a type writing machine equipped with the device, forming the subject matter of this invention. l

Figs. 2 and 3 are side views showing different positions of the locking members and the shifting roll.

Figs. 4 and 5 and 6 show similar views-of a second embodiment of this invention and correspond to Figs. 1 to 3. i

Referring first'to the form of construction, illustrated in Figs, 1 to. 3, the platen frame is arranged vertically adjustable in a known manner in the carriage frame 1, said platen frame consisting in the construction shown substantially of two side plates 2, which are connected with each? other by fixed brace rods 3, 1 and 5. The brace rod 5 carries by means of the pivoted arms 6 a rod 7, upon which acts the shifting roll 8. I On one of said arms 6 or on both set screw 12, which is provided in a bracket of the plate 2, in such a manner, that when the arm 6 strikes against the setscrew the pawl 9 is barely out of reach of the pin 11 (Fig. As long as the roll 8 which 1s connected with the shift key is not raised an unintentional vertical displacement of the f *ame of the platen 18 in relation to the frame of the carriage cannot occur, as both parts are locked against each other by the pawl 9 and the pin 11. However, when by the operation of the shift key the roll 8 1s lifted, first the rod '7' with the arm 6 and the pawl 9'is oscillated aroundthe brace rod 5, so far until the arm 6 strikes against the set screw 12. Then the unlocked platen frame can be lifted by means of the shifting roll.

In the second form of construction of the subject matter of the invention, shown in Figs. 4 to 6, the shifting roll lifts the platen frame by means of an angular rail 13 rigidly connected to said platen frame. In front of this rail a secondrail is arranged, which is also located within the reach of'the shifting roll 8 and which can be adjusted by said shifting roll, said rail 14: being connected to the angle lever 15, which can oscillate aroundthe pin 19 and acts as a locking pawl. The pawl or angle lever 15 looks by means of the adjustable screw 16 in the same manner as this is done in the first described form of construction by means of the pawl 9.

At the depression of the shift key first the correspondingly adjusted rail 14 is lifted (Fig. 5), whereby the platen frame is unlocked, so that now by the action of the shifting roller 8 also the rail 13 can be lifted.

On account of the fact, that the much used shifting rail'is rigidly connected with the platen frame, a more uniform writing in comparison to the first described form of construction is obtained,

The pawls 9 or 15 respectively of both forms of construction can be moved into the locking position either by the weight of the rail 7 or 14 respectively or also with. the aid of springs.

It is practical, if desired, to provide the left end as well as the right end of the rail 14 with a locking pawl.

Having thus particularly described the nature of my said invention, what I claim as new and desire by Letters Patent of the United States is:

1. In a typewriting machine in combination a carriage, a platen frame mounted in said carriage normally in lower case position but vertically movable relative to said carriage to upper case position, a latch carried by said platen frame and engageable with said'carriage to hold said platen frame and carriage relatively fixed when in lower case position, said latch being constructed tobe free from contact with any element extraneous to the platen frame during return movement of said frame to permit frictionless return of the latter.

2. In a typewriting machine, in combination, a. carriage, a platen frame mounted in said carriage normally in lower case position but vertically movable relative to sald carriage to upper case position, said frame being provided with a slot, a stop on said frame, a latch comprising a bell crank lever pivotally mounted on said frame and normally having one of its arms in alignment with said slot and the other spacedv from said stop, a pin secured to said carriage projecting through said slot and normally e-ngageable by the arm of said bell crank lever, means engageable with said bell crank lever, to rotate the same sequentially out of engagement with said pin and into engagement with said stop for releaslng said latch and shifting said platen frame relation to said carriage.

3. In a typewriting machine, in combination a carriage, a platen frame mounted in said carriage normally in lower case position, but vertically movable relative to said carriage to upper case position, said framebeing provided with. a stop, a latch comprising a bell crank lever pivotally mounted in said frame having an armengageable with. said step, a projecting element secured to said carriage and normally 'engageable by the other arm of said bell crank lever, means for oscillating said bell crank lever. to sequentially release said last named arm from engagement with said projecting element and moving the first mentioned arm into engagement with said stop for shifting said platen frame.

a. In typewriting machine, in combination, a carriage, a platen frame mounted in said carriage normally in lower case position but vertically movable relative to said carriage to upper case position, said frame comprising end plates connected by a brace rod, latch mechanism pivotally mounted on said brace rod adjacent each of said end plates comprising bell crank levers one arm of each lever being connected by a shift rod for elevating said platen frame, a stop on each end plate engageable by said arm of the bell. crank lever, a pin secured to the carriage at each end and engageable by the other ends of said bell crank levers, a shift lever movable into engagement with shift rod to move said bell crank levers to sequentially release said bell cranks from said pins and move them into engagement with said stops for shiftingsaid platen frame.

5. In a typewriting machine, in combination a carriage, a platen frame mounted in said carriage normally in lower case position, but vertically movable relative to said carriage to upper case position, said-frame being provided with a vertically disposed slot, an adjustable stop on said frame, a latch comprising a bell crank lever pivotally mounted in said frame, one arm thereof being in alignment With said slot and the other arm being in the path of said stop, a spring for normally holding the first named arm of said bell crank lever in the path of said slot, an element secured to said carriage projecting through the slot, a shift lever for said frame engage-able with said bell crank lever to sequentially release the first named arm from said projecting ele- 10 ment and put the other arm of said bell crank in engagement with said stop to shift said platen frame.

In testimony whereof I have hereunto set my hand in presence of tWo subscribing Witnesses.

HEINRICH FRANZ EDMUND BAESELER.

Witnesses HEINRICH GI'INER, WILHELM BLEsHEN. 

